The present invention relates to a cassette cover opening mechanism for a magnetic recording/reproducing apparatus and, more particularly, for a video tape recorder (VTR).
A tape cassette for use in a VTR generally has a box-like case in which a magnetic tape wound on a pair of reels is housed. The front side of the cassette case opens to define a tape loading port. The tape loading port is opened/closed by a cassette cover which is pivotally mounted on the cassette case. The cassette cover has a front plate for opening/closing the tape loading port and a pair of side plates extending from the two ends of the front plate. The side plates are pivotally mounted on the side surfaces of the cassette case. The cassette cover is normally biased by a coil spring or the like to keep the tape loading port closed.
When the tape cassette is to be loaded in a tape recorder, the cassette is first inserted into a cassette holder. Then, the cassette holder holding the cassette therein is pressed to the drive position. While the holder is moved downward, the cassette cover is pivoted upward since the lower edge of the front plate abuts against a cover opening member of the tape recorder. Thus, the tape loading port is opened. Thereafter, part of the magnetic tape inside the cassette is drawn out through the tape loading port and is engaged with a driving means, a transducer and the like of the tape recorder.
However, in a conventional mechanism, the opening member abuts against the cassette cover after the cassette holder is moved downward considerably, so that the cassette cover starts to be opened at a relatively late timing. For this reason, the cassette holder may move to the lowermost position before the cassette cover fully opens. In this case, if a guide post, a loading post or the like is arranged below the cassette cover, the cover may abut against the post or the like. When the cassette cover is not fully open, the drawing operation of the magnetic tape may be interfered with. With the recent trend toward smaller and thinner tape recorders, the downward stroke of the cassette holder is becoming shorter. The above-mentioned problem is more notable if the downward stroke is shorter.
The level of the cover opening member can be raised so as to open the cassette cover at an early timing. However, in this case, the opening member is caught by the front plate of the cassette cover, and the cassette holder cannot be moved to the drive position. For this reason, the adjustable range of the position of the opening member for the purpose of opening the cassette cover at an early timing is limited.